Someone asked me to comment on Zeiss 15mm f2.8. I have decided to compare it my other favorite short lens - the TS-17. The TS-17 is a very good lens

A comparison is:
Zeiss f2.8 is twice as fast
Zeiss has hard stop at infinity and canon goes beyond
Canon has shift which permits easy stitching or removal of UWA bowing of trees
Canon has tilt which I use very little because 17 has pretty good depth at f8 anyway and the plane has to be flat and its challenging to use
They are both manual focus
They are both heavy
The zeiss can take a very expensive filter whereas the TS/17 requires extensive work to create filters manually
The TS/17 has a very large protruding lens that is subject to flair more than the Zeiss
They are both pretty expensive - Canon $2200, Zeiss $2900

My conclusion is that zeiss is really good. I prefer TS/17 if there is no star trails (not night shooting) because of the versatility of tilt/shift, quality and ability to avoid bowed trees. In addition, when you shift horizontally from 1 extreme to middle to other extreme and take it into photoshop, it stitches perfectly without any waste to deliver a 11mm wide pano. And if you put the 1.4x on, it works well as a 24mm TS.

But at night, the twice as fast is important for lower ISO and avoidance of star trails.

Surprisingly the zeiss 15 seems to perform better in corners than the TS17 or TS24.

Anyway I am happy with both my lens - just passing along my thinking.

Scott

First the reference - TS17 on Bow River - at f11 - uncropped focussed near horizon

For reference according to photozone.de the TS 17 has very little distortion, low vignetting, and quite high resolution at centre and borders ( >3000), putting it at one of the best UWA. However it performs less well when shifted and if you shift to extreme it starts losing resolution. As long as you keep it to 10/12 it seems to do well on the shift.

Comparing it to samyang 14 2.8 - the samyang has about 10% higher resolution but very high distortion and vignetting that requires lots of post processing correction.

Comparing it to the other great uwa nikon 14-24 with high 3000's resolution, the TS 17 is within 20% of resolution with way less vignetting and distortion.

So the Zeiss 15 must be pretty good to keep up and exceed the resolution in corners of TS17.

I did not check to see how far I shifted on the sample so I might have given the TS/17 a handicap but phtozone says that it can reach 3500 centre and 3000 border at f5.6 as compared to 4000 and 3500 respectively for the Nikon.

If the middle pictures of the 15, 17, and 24 all show the same extent of the scene, that means that 2 of the three and possibly all three have been run through some resizing software. In other words, there is some magic behind the curtain that hasn't been detailed.

I would rather see the 100% crop pixels, unadulterated.

Have you done the same thing with the corner pictures? Can we see 100 % crop pixels, unadulterated?

Are you using the Mk I or Mk II version of the TS-E 24/3.5L lens? I've compared the TS-E 24/3.5L II and Zeiss 21/2.8 ZE, and found they have very similar performance in the corners. Here's one example taken in Jan 2012, comparing 100% portions of lower left corners on a 1DsIII. The TS-E 100% crop is from the absolute corner of the image, while the ZE image is slightly "in", because of its wider FOV. The images are not resized, and so what you see is what you get.

I think the TS-E is slightly cleaner than the ZE, but they're both excellent.

If the middle pictures of the 15, 17, and 24 all show the same extent of the scene, that means that 2 of the three and possibly all three have been run through some resizing software. In other words, there is some magic behind the curtain that hasn't been detailed.

I would rather see the 100% crop pixels, unadulterated.

Have you done the same thing with the corner pictures? Can we see 100 % crop pixels, unadulterated?

They were shot in raw so they have to be processed by something. I imported these into aperture, then duplicated twice and cropped one to middle and one to bottom edge. So its resized in aperture by cropping. And exported at jpg 1024 x 1024.

What do you suggest for a better cropping - I could use DPP to process and then open photoshop and go actual pixels and then crop and post.

Scott, from the example photo you posted, I would say you either have a bad copy of the 17 TS-E, or perhaps you didn't have the tilt lock engaged...?

I noticed a few of my shots weren't quite tack-sharp with the 17 TS-E, and discovered that if you don't use the tilt lock and don't have the lock knobs really tight, the front of the lens can sag a tiny amount, just enough to cause slight unsharpness in the image.

Regarding filters, my take on the comparison is that the Zeiss 15 is limited to using 95mm screw-in filters only (very expensive polarizers, no graduated filters) while the Canon TS-E can use the Lee filter system, allowing the use of graduated filters as well as the (also very expensive) Lee 105mm polarizer, albeit with limited shift capability.

molson wrote:
Scott, from the example photo you posted, I would say you either have a bad copy of the 17 TS-E, or perhaps you didn't have the tilt lock engaged...?

My tilt lock is always engaged. However, the TS17 might have been shifted 1/3 way so that is a bit of a handicap.

I suspect that the zeiss has more field curvature and when you focus at near infinity the field of focus on the edges is further back.

One of the things I realize in this testing is that you have to make lots of choices in comparing (like where to focus and focus is critical).

The thing to keep in mind is that I am comparing a $2900 dollar, best in class prime non tilt with a $2200 best in class tilt. When you crop as much as I did they are going to look bad. You may have cropped less?

I have both lens and am going to try another time, because I am concerned that my ts17 was shifted a bit and the exposure was a bit different, so any suggestions about:
1) Whats fairest for where to focus in scene
2) Whats fairest height above ground 15mm in theory is effectively further from the ground
3) What fstop - photozone suggests that TS17 is sharpest at f5.6
4) What resizing technique.